ES 3- Electrolysis 0.0 / 5 ? ChemistryelectrolysisASOCR Created by: anabobCreated on: 18-01-18 21:18 define electrolysis when electricity is passed througha molten/aqueous ionic compound, breaking it down 1 of 15 why must the ionic compound be molten or aqueous? so the charged ions are free to move and carry a current 2 of 15 which ions move to the cathode? POSITIVE (cations) ions 3 of 15 where do NEGATIVE (anions) ions move? anode 4 of 15 at which electrode does reduction occur? cathode 5 of 15 what are the products at each electrode? cathode- metal, anode- non metal, apart from hyrdogen 6 of 15 why is it different to predict products at electrodes for the electroylsis of solutions as opposed to molten compounds? water can be reduced at the cathode (makes OH- and h2)or oxidised at the anode (makes o2, H+ and e) 7 of 15 when would hydrogen be made at the cathode? when the metal there is more reactive so water is reduced instead 8 of 15 when would halogens be made at the anode? halide ions have a gretaer tendency to be oxidised than water 9 of 15 when would oxygen be made at the anode? other negative ions like sulphates or nitrates are less likely to be oxidised than water 10 of 15 which electrodes are most commonly used? graphite and platinum 11 of 15 why does the metal anode lose mass during the elecrrolysis of copper with a copper anode? copper atoms change to copper ions and go into the solution. The copper is deosited at the cathode 12 of 15 what is found at the anode if it's a hydroxide that's electrolysed? oxygen 13 of 15 what is the half equation for the product at the cathode if the salt is gorup 1/2 or is Al? 2h2o +2e- ---> 2oh- + h2 14 of 15 what's the half equation for the product at the cathode for the electrolysis of an acid? 2H+ +2e- ---> h2 15 of 15
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